Introduction

Warts are small, skin-coloured, rough lumps on the skin. They often appear on the hands and feet and look different depending on where they are on the body and how thick the skin is. A wart on the sole of the foot is called a verruca. Genital warts are warts found on the genitals and around the rectum.

Warts are caused by infection with a virus called human papilloma virus (HPV). The HPV virus causes a hard protein called keratin in the top layer of the skin (the epidermis) to grow too much, producing the rough, hard texture of a wart.

Warts are usually harmless, but they can look unattractive. They often clear up by themselves, although treatment can help to get rid of them more quickly. Warts arent normally painful, although verrucas can sometimes hurt.

Symptoms

Warts can be different sizes, ranging from 1mm to over 1cm. You may have only one or two warts, or lots can develop on the same area of skin.

The size and shape of warts varies:

Genital warts (condylomata acuminata) can be small, white lumps or larger, cauliflower-shaped growths on the penis, scrotum or vulva (the female external sex organs), or around the rectum. Warts can also develop inside the vagina or anus.

Genital warts on the vulva are usually soft because the skin here is moist and hairless. Genital warts that develop on skin that is dry and hairy (such as the shaft of the penis) tend to be firm. The number of warts that develop varies. Some people have a few that are hardly noticeable, while others have a lot. Genital warts do not usually cause any symptoms, although they may be itchy if they are around the anus. However, the warts may be a sign of a sexually transmitted infection (STI), or, in rare cases, cancer.

Causes

Warts are caused by different strains of the human papilloma virus (HPV). The virus is present in the skin cells of a wart, and can be passed on through close skin-to-skin contact.

You are more likely to catch the infection if your skin is damaged, or if it is wet or in contact with rough surfaces. For example, public swimming pools are a common place to catch verrucas. People with scratches or cuts on the soles of their feet are especially vulnerable.

You can also spread warts to other parts of your own body. For example, if you scratch or bite a wart it can cause the wart to break up and bleed, making it easier for the virus to spread.

People with a weak immune system (as a result of immune system diseases such as AIDS, or as a result of certain treatments such as chemotherapy) are more likely to catch warts. They may develop lots of warts that are particularly difficult to get rid of.

Genital warts are caused by a strain of the HPV virus that is passed on during sex, or very close sexual contact. However, most people infected with HPV dont develop visible warts. You can carry the virus without realising it, and pass it on to other people who may then go on to develop visible genital warts.

Diagnosis

Warts and verrucas are easy to recognise. Warts are usually raised growths with a hard uneven surface. A verruca may have been pushed in by the weight of your body and so appear as an area of very white skin on the sole of your foot, perhaps with a black dot in the centre.

Although genital warts can be embarrassing, it is important to have them checked out at your GP surgery or local sexual health (GUM) clinic.

Treatment

Most warts clear up without treatment, although this can take up to two years. There are treatment options available that may be able to clear warts faster, although some types of treatment can be painful, and there is no guarantee that the warts wont come back again.

Treatment options depend on where the warts are and how many there are. Options include:

Chemical treatments– Treatments containing a chemical podophyllilotoxin can be used to remove warts. These chemicals are poisonous to skin cells they are dabbed onto warts to kill the skin cells there. These treatments are available on prescription.

Cryotherapy– Very cold liquid nitrogen is sprayed onto the wart to freeze and destroy the cells. A sore blister develops, followed by a scab, which falls off 7-10 days later. Treatment takes about 5-15 minutes and can be painful, so you might need a local anaesthetic beforehand. Cryotherapy treatment is usually carried out at hospital skin clinics or at your GP surgery. Large warts sometimes need to be frozen several times, a week or so apart, before they clear.

Surgery– Surgery to remove warts is carried out under general or local anaesthetic. Warts can be cut out of the skin (useful for a few, large warts), or the skin of the wart can be scraped off with a spoon-like instrument called a curette. The aim of surgical treatment is to remove all traces of the warts.

Other surgical options are laser treatment– in which the wart is destroyed using a very precise laser beam – and electrocautery, in which the wart is burnt off using an electric current.

If you have genital warts, you should not try to treat them yourself with over-the-counter medicines. You must see your GP or visit your local GUM clinic for treatment. Genital warts can usually be removed using techniques similar to those described above. The method used will depend on how big the warts are and whether they are inside your body or on the skin surface.

Whatever the treatment used, it usually takes several weeks to clear genital warts and can sometimes take up to six months.

Prevention

To reduce your risk of getting warts:

Don’t touch other peoples warts

Don’t scratch or pick at a wart as this may spread the infection to other parts of your body

Don’t share towels, flannels or other personal items with a person who has a wart

If you have a verruca, you should cover it with a plaster when you go swimming. If you have a wart on your hand you should wear gloves if you are using communal equipment (for example, in a gym).

To avoid catching genital warts, you should practice safe sex. The best way to do this is to use condoms. However, condoms dont cover the entire genital area, and are usually put on after sexual contact has begun, so the virus that causes genital warts can still be passed on.

You should use a condom (as well as any other form of contraception you normally use) for 3-6 months following treatment for genital warts. This helps to stop you and your partner getting re-infected.

This has been adapted from ‘Sexual Health Birmingham’ the authors are Dr S Acharya & Dr J Arumainayagam.

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